Major Element Distribution, Sources, and Geological Significance in Surface Sediments of Dongping Lake, China

The geochemical characteristics of major elements in lake sediments provide insights into aquatic environmental variations, the regional geological background, and the intensity of weathering processes. This study investigates Dongping Lake (DL) using 20 surface sediment samples, analyzing nine major elements. Spatial interpolation was used to characterize their distribution patterns, while principal component analysis, self-organizing maps, and absolute factor analysis–multiple linear regression methods were applied to identify element sources and interpret their geological significance using weathering indicators. Results show that surface sediments are dominated by SiO2 (46.49%), Al2O3 (13.10%), and CaO (11.25%). Controlled by hydrodynamic conditions, major elements are mainly concentrated in the southern part of the lake near the inflows of the Dawen and Liuchang Rivers, with concentrations decreasing from south to north. Riverine transport is the primary source of major elements, with the Dawen River contributing the most followed by the Liuchang and Yellow rivers. Weathering indicators suggest that source rocks have experienced moderate chemical weathering, reflecting initial sedimentation in a tectonically active setting under warm and humid conditions and relatively short transport distances. These findings provide a geochemical basis for understanding sedimentary processes and environmental evolution in the Dongping Lake basin and offer valuable support for regional water resource management, ecological restoration, and sustainable watershed governance.